Merchants of Despair: Radical Environmentalists, Criminal Pseudo-Scientists, and the Fatal Cult of Antihumanism, by Robert Zubrin (Encounter, 328 pp., $25.95) A ruling idea of the last two centuries has been materialism: the notion, as arch-materialist Daniel Dennett asserts, that Â“there is only one sort of stuff, namely matterâ€”the physical stuff of physics, chemistry, and physiologyâ€”and the mind is somehow nothing but a physical phenomenon.Â” One consequence of this belief has been the rise of antihumanismâ€”the stripping from people of their transcendent value and a reduction of them to mere things in the world to be studied, understood, reshapedâ€”and ultimately...